Comparison of different wastewater treatments for removal of selected endocrine-disruptors from paper mill wastewaters

Abstract

There is increasing concern about chemical pollutants that have the ability to mimic hormones, the so-called endocrine-disrupting compounds (EDCs). One of the main reasons for concern is the possible effect of EDCs on human health. EDCs may be released into the environment in different ways, and one of the most significant sources is industrial wastewater. The main objective of this research was to evaluate the treatment performance of different wastewater treatment procedures (biological treatment, filtration, advanced oxidation processes) for the reduction of chemical oxygen demand and seven selected EDCs (dimethyl phthalate, diethyl phthalate, dibutyl phthalate, benzyl butyl phthalate, bis(2-ethylhexyl) phthalate, bisphenol A and nonylphenol) from wastewaters from a mill producing 100 % recycled paper. Two pilot plants were running in parallel and the following treatments were compared: (i) anaerobic biological treatment followed by aerobic biological treatment, ultrafiltration and reverse osmosis (RO), and (ii) anaerobic biological treatment followed by membrane bioreactor and RO. Moreover, at lab-scale, four different advanced oxidation processes (Fenton reaction, photo-Fenton reaction, photocatalysis with TiO₂, and ozonation) were applied. The results indicated that the concentrations of selected EDCs from paper mill wastewaters were effectively reduced (100 %) by both combinations of pilot plants and photo-Fenton oxidation (98 %), while Fenton process, photocatalysis with TiO₂ and ozonation were less effective (70 % to 90 %, respectively).

Keywords:

• Advanced oxidation processes
• anaerobic and aerobic biological treatment
• endocrine-disruptors
• membrane filtration
• paper mill wastewaters

Acknowledgment

This work was performed within the framework of the projects “PROLIPAPEL” (P2009/AMB-1480), funded by the Regional Government of Madrid, Spain; “AGUA Y ENERGÍA” (CTM2008–06886-C02–01) funded by the Ministry of Science and Innovation of Spain; and “AQUAFIT4USE” (211534), funded by the European Union. This work was also funded by the European Social Fund (grant No. MR-32/07). The authors are grateful for all the support.